Pressure-stopper for chain cables



UNITED STATES PAT NT OFFICE.

PRESSURE-STOPPER FOR CHAIN CABLES.

Specicaton of Letters Patent No. 13,593, dated September 25, 1855.

To all 10h-omit may concern,

Be it known that I, JAMES EMERSON, of Vorcester, in the county of lorcester and State of Massachusetts, have invented a new and useful Improvement in Pressure-Stoppers for Chain Cables to be Applied to W'indlasses; and I do hereby declare that the following yis a full, clear, and exact description of the same, reference being had to the annexed drawings, making a part of this specicat-ion, in which- Figure 1, is a longitudinal vertical section of my improvement, a chain being shown in the device. Fig. 2, is the same view as Fig. l, the chain being removed. F ig. 3, is a front view of ditto.

Similar letters of reference indicate corresponding parts in the several figures.

My improvement has reference to that class of chain Stoppers in which, to do away with the shock and liability to breakage consequent upon an abrupt pawl or similar stop being applied to the chain, a pressing action is used to bear upon the chain to retard by friction the run of the chain and, on increase of the pressure, to secure, either in connection with a pawl or not, to hold or stop the chain entirely. Some of these pressure stoppers have consisted of a pawl on one side, with notch in it to allow of the vertical links of the chain passing through while the pawl bit on or acted against the horizontal links, and a vertical upper sliding block behind the pawl and serving upon screw pressure being applied to grip the chain against or on a similarly grooved under block. Other arrangements have consisted of an upper jaw and under bed pieces, both of such a length as to take in between them, in one continuation or line, several links of the chain, and so constructed as to bite or bear upon the links upon pressure being applied to the Lipper jaw by lever connected therewith, the upper liaw being hinged at or along its one side or edge or otherwise being equivalently arranged to open and close by a parallel or other movement, and in some of these instances the end of the upper jaw has been made to perform, to a limited extent, upon eXtreme pressure being applied, the functions of a pawl to make certain and firmer the grip or hold of the chain.

It is to this latter arrangement of stoppers in particular that my invention more immediately relates and my improvement consists in a novel construction and arrangement of the parts as will appear from the following minute description of the details of the stopper and their operation for the most part common to the other pressure stoppers here referred to.

A, represents a metallic bed plate to one end of which a jaw B, is secured by a bolt or pivot, a, the jaw working on the bolt or pivot. The under surface of the jaw B, as well as the upper surface of the bed plate has a longitudinal groove Z), made in it through which the upright links, c, of the chain C, pass, the horizontal links rl, pass between the under surface of the jaw and the upper surface of the bed plate. The chain C, is of usual construction, every alternate link being in an upright` or vertical position, and the intermediate links in a horizontal position, consequently the grooves, Z), are necessary in order to allow the vertical links, d, to pass between the jaw and bed plate.

D, is a pawl, the upper end of which is secured by a pin, e, to the jaw B, the lower end of the pawl D, has a'recess, f, in it through which the upper sides of the vertical links, c, pass.

E, is a lever which is attached by a pin, g, to the front part of side pieces, 71 attached to the bed plate A, and F, is a link or arm at the lower end of the lever, one end of which link or arm is connected by a pin, z', to one end of the jaw B, and the opposite end has a slot in it through which the pin, g, passes.

The device above described is to be attached to a windlass, one or more devices being attached to a windlass according to the number of chains used, while the chains are being drawn in or wound up, the aw B, may be raised or thrown upward, but while the chain is being let out the jaw B, is thrown over upon the bed plate, as shown in the drawings. If it is desired to check or retard the motion of the chain the upper end of the lever E, is turned around by hand a certain distance in the direction indicated by the arrow 1, and the jaw B, will be pressed down upon the chain C, both the vertical and horizontal links being subjected to pressure, and if it is desired to stop the chain entirely the lever E, is still further depressed and the pawl D, will catch against the upper sides of the vertical links and effect the object. i

Now it will be observed that in applying the stopper to retard and stop the run of the Chain out, not only are both the vertical and horizontal links subjected to pressure by the specilied configurations of the jaw and bed plate, but by hinging the jaw at the one end of the stopper (instead of at the side or otherwise equivalent hanging it) and arranging the paWl near the other' or opposite and opening end, a more gradual and stronger pressure action is obtained by reason of the bite or rub gradually taking place from the ulcruln end of the jaw (Where strainage or jerk is better borne) toward the other end throughout'the length of the jaw, and the paWl niore effective-ly cornes into action on extreme pressure by reason of its arrangement near the opening end of the jaw Where the motion is greater and action consequently more gradual than at the ulcruin and stronger end which bears the irst and heavy rub or jerk, and the pavvl is thus better relieved of severe and injurious strainage; and the pawl is quicker relieved in raising the jaw to run out the chain before all pressure of the jaw is removed. This protects the pavvl 'from breakage.

. W hat I clailn as new and useful herein, and desire to secure by Letters Patent is- The arrangement of the jaw hinged at its one end and having a pawvl at or near the other, With the bed plate, `for operation together, and 'the Whole being Constructed, Substantially as specified.

JAMES EMERSON.

Witnesses P. EMoRY ALDRICH, C. R. HAYWooD. 

